Details

Autor(en) / Beteiligte

• Wang, Norman C., MD, MS
• Singh, Madhurmeet, DO
• Adelstein, Evan C., MD
• Jain, Sandeep K., MD
• Mendenhall, G. Stuart, MD
• Shalaby, Alaa A., MD, MSc
• Voigt, Andrew H., MD
• Saba, Samir, MD

Titel

New-onset left bundle branch block–associated idiopathic nonischemic cardiomyopathy and left ventricular ejection fraction response to guideline-directed therapies: The NEOLITH study

Ist Teil von

• Heart rhythm, 2016-04, Vol.13 (4), p.933-942

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2016

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• Background Left ventricular ejection fraction (LVEF) response to guideline-directed medical therapy (GDMT) and to early cardiac resynchronization therapy (CRT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) and left bundle branch block (LBBB) is not well described. CRT is recommended if LVEF remains ≤35% after at least 3 months of GDMT. Objective The purpose of this study was to describe LVEF response to GDMT at 3 months and to early CRT in new-onset LBBB–associated idiopathic NICM. Methods A retrospective cohort study was performed in subjects with new-onset idiopathic NICM, LVEF ≤35%, and LBBB or narrow (<120 ms) QRS complex morphology. LVEF response between groups was evaluated with log-binomial and linear regression. LVEF response within groups was evaluated using the paired Student t test. Results In 102 subjects (70 with narrow QRS complex and 32 with LBBB), post-GDMT LVEF was >35% in 39 narrow QRS complex subjects (56%) and 2 LBBB subjects (6%) (P < .0001). The absolute difference between post-GDMT LVEF and initial LVEF was greater in the narrow QRS complex group (16.1% ± 14.6% vs 3.3% ± 10.7%; P < .0001). Narrow QRS complex, referenced to LBBB, was significantly associated with post-GDMT LVEF >35% (relative risk 10.30; 95% confidence interval 2.63–40.27; P = .0008) and absolute difference between post-GDMT LVEF and initial LVEF (β = 16.296; standard error = 2.977; P < .0001) in final multivariable analyses. CRT super-response, defined as post-CRT LVEF ≥50%, was observed in 8 of LBBB subjects (35%) who received CRT. Conclusion GDMT did not significantly improve LVEF in new-onset LBBB–associated idiopathic NICM at 3 months. Most remained candidates for CRT, and a high percentage were super-responders. Optimal timing for CRT implantation requires further investigation.